Yazaki Corporation

Din-Guo Chen

Yongan Yan

Yoshitake Sato

Satyabrata Raychaudhuri

Arnab Sarkar

A process is described for applying a thin-film, hydrophobic, oil-repellant, stain-resistant, optical coating to a transparent substrate. The coating is applied using a treatment solution that incorporates an organosilane in a solvent of water, alcohol, and ethylene glycol or glycerol, and an acid catalyst, with the organosilane having a preferred concentration in the range of 0.05 to 50 mmole per liter. The treatment solution preferably is prepared in a two-step procedure, in which the organosilane is first reacted in concentrated form and then diluted. After the treatment solution has been applied to the transparent substrate, e.g., by dip coating, the coated substrate is dried, preferably by flash-drying at room temperature and then heating it to a prescribed elevated temperature, in a prescribed humidity.

Transparent substrate bearing an anti-stain, hydrophobic coating, and process for making it

A coated transparency, and method for making it, is disclosed, the transparency having a multi-layer antireflection coating that provides high transmittance with low specular reflectance, yet that also provides reduced visibility of surface defects. The coating includes alternating layers of polymerized silicon dioxide and polymerized titanium dioxide on a transparent substrate, with at least one of the layers incorporating discrete particles having a refractive index different from that of surrounding polymer. This provides the coating with a diffuse reflectance that is comparable to, or larger than, its specular reflectance, yet that still is negligible when compared to the coating's transmittance. The diffuse reflectance creates a loss of contrast for any reflected image or glare, thus masking any surface defects and providing a comfortable visual appearance. The successive layers of the antireflection coating are deposited on the substrate by applying separate solutions of an alkoxide, an alcohol, and water, and by curing the layer at an elevated temperature before the next succeeding layer is applied.

Process for making a optical transparency having a diffuse

A sol-gel process is disclosed for depositing multi-layer antireflection coatings on plastic substrates. One or more polymerized, titanium-containing solutions are provided by mixing a titanium alkoxide, an alcohol, and water, and one or more polymerized, silicon-containing solutions are provided by mixing a silicon alkoxide, an alcohol, and water. These solutions are applied to the plastic substrate in an alternating fashion, to produce a succession of uniform layers of polymerized titanium dioxide and polymerized silicon dioxide. Each layer is individually cured before the next layer is applied. The resulting coating of multiple polymerized layers provides very low reflectance over the entire visible wavelength range, yet with excellent mechanical strength and durability.

Growing community of inventors

Agoura, CA, United States of America

Din-Guo Chen